Material extrusion is a commonly used additive manufacturing technology that involves heating and extruding thermoplastic filament and depositing the extruded material onto a build plate creating a three dimensional model one layer at a time. In these additive manufacturing processes, current methods of extrusion include, but are not limited to, direct drive extrusion and remote drive extrusion. In a direct drive extrusion process, the driving unit is directly connected to the heating component and extrusion nozzle. In an indirect drive extrusion process, the driving unit is mounted remotely and the filament is guided to the heating component and extrusion nozzle via flexible tubing. Feed rate and speed are difficult to optimize in either of these processes due to the need for additional compression of the drive rolls as feed rate and speed increase. Before optimal feed rate and speed can be reached, required drive roll compression can cause damage to the filament.
U.S. Pat. No. 5,121,329 describes an early apparatus and method for creating three-dimensional objects. The '329 patent sets forth basic principles regarding additive manufacturing and drive systems, and is hereby incorporated herein by reference in its entirety.